Samsung UE55KS8090 - Mainboard replacement failed

[Hauke]

Hello guys,

I bought this awesome 55" Samsung TV. The problem was, that it tried to start but did this indefinitely.

I found a relatively cheap mainboard from a 65" KS8090 with broken panel and bought it. It is mechanically identical.
After mainboard replacement the TV started again. I was able to pair the smart remote and I could hear sound.

The problem is, that the TV does not show the right image. It only shows vertical colored bars.
The colored bars change with the content that should be displaced on the screen.
Sometimes they are all over the screen and sometime only in the middle or at one side.

I flashed two EEPROMs (W25Q40 and W25Q80) with the software from remont-aud: https://****************/dump/crt_tv.../102-1-0-63971
This dump was from an UE55KS8000. At the moment I can't flash the 24C512.

But the problem stays the same. The TV works, but the displayed picture ist wrong.
I attached some pictures of the mainboard and the weird displayed image.

Has someone any ideas? I don't know what to try next.

Thanks!

Hauke

[budm]

Re: Samsung UE55KS8090 - Mainboard replacement failed

So was the TV working correctly at all after you bought it?

[Hauke]

Re: Samsung UE55KS8090 - Mainboard replacement failed

I bought it as defect. The owner said the TV suddenly won't start anymore.

It tried to start without showing any picture and then shut down and tried starting again. There was no difference if the one connect box was connected or not. And there was no sound.

Edit: I added some pictures.

[Moreno83]

Re: Samsung UE55KS8090 - Mainboard replacement failed

Well to be honest this could be 2 things.

1) Bad t-con ( if available )
2) Bad panel.

Did you check the boards connected to the panel for liquid damage? There are people out there that clean tv's with water hahaha.

[Hauke]

Re: Samsung UE55KS8090 - Mainboard replacement failed

@Moreno83: Oh no, that would be very sad..
There is no real T-Con board like it is in other TVs.

I asked the seller of the new mainboard and he said, that he also wanted to repair his 55" TV with this mainboard. He told me, that he had vertical bars, too. He thought his panel was dead and so he sold the mainboard.

Maybe the "new" mainboard is defective? Could this really be caused by a bad mainboard with integrated t-con? If yes I would try to buy a brand new mainboard for about 150€.
What would you say? Would you risk it?

[Beau28713]

Re: Samsung UE55KS8090 - Mainboard replacement failed

Could it be possible that the 55 inch and 65 inch use different main CPU chips on the main board? Even if it is the same board part number it may be a different revision. This could possible cause the lines.

[Hauke]

Re: Samsung UE55KS8090 - Mainboard replacement failed

Could it be possible that the 55 inch and 65 inch use different main CPU chips on the main board? Even if it is the same board part number it may be a different revision. This could possible cause the lines.

I checked the CPU chips. Maybe you are right.
Both boards use "SDP1501 Jazz-M" chips, but the the original mainboard has a "S4B4PL S1622" and the new board has a "S5K56QD S1730".
I will try to find the datasheet and look what these numbers mean.

[Diah]

Re: Samsung UE55KS8090 - Mainboard replacement failed

SDP1501 Jazz-M both same.usually the integrated T-CON located at the panel taps not on the main boards.. back to post #4 and inspect the panel taps this should be the first things you need to do right now.

[Hauke]

Re: Samsung UE55KS8090 - Mainboard replacement failed

Ok, ich checked the panel taps. They looked good.

I got a little deeper into troubleshooting. I bought a UE55KS9090 with a broken panel really cheap. I read, that the only difference between my model and this broken unit is the curved frame.

I took out the mainboard and put it into my TV. I got these colored lines again.
Then I put my replacement mainboard in the TV with broken panel and now this unit displays colored vertical lines too. After putting in the original mainboard the screen was normal again.

It looks like the mainboards aren´t exchangeable..

[nomoresonys]

Re: Samsung UE55KS8090 - Mainboard replacement failed

Kind of looks like the mainboard you bought is defective???

[William1967]

Re: Samsung UE55KS8090 - Mainboard replacement failed

Every type of display has it's own screencode, a 65"has another code than a 55" so I guess that's wil be the problem.

[Hauke]

Re: Samsung UE55KS8090 - Mainboard replacement failed

Kind of looks like the mainboard you bought is defective???

I don´t really know. The mainboard from the TV with broken panel also creates vertical colored lines in my TV.

Every type of display has it's own screencode, a 65"has another code than a 55" so I guess that's wil be the problem.

Yes, but the mainboard of the 55" TV with broken panel does also not work in my TV.


After reflashing all EEPROM and Flash ICs on my original mainboard it starts. Now I can hear the starting sound and the backlight comes up. But the panel stays black.

[nomoresonys]

Re: Samsung UE55KS8090 - Mainboard replacement failed

Ok, borked firmware strikes again, looks like you're making progress, now maybe try a reset.

[nomoresonys]

Re: Samsung UE55KS8090 - Mainboard replacement failed

One reset procedure here, not sure if it will work with your model:
While the TV is On, press and hold the EXIT button on the Samsung remote control for 12 seconds. The standby light should blink the entire time without interruption.
The Factory Reset screen displays a warning message. Select OK to reset the TV.

Also try this one:

Make sure that your TV is OFF.
Take your Smart Remote and simultaneously press Info + Menu + Mute + Power.
Next, enter the following sequence into your remote: Mute > 1 > 8 > 2 > Power.
Your television will boot up in service mode. Using your remote, go to Options > Factory Reset.

Your television should now turn off and a simple restart should proceed with the setup.

This maybe difficult in your case since you can’t see the screen. Samsung has had plenty of issues with firmware updates that bricked their TV’s. You do wnat to go ahead and call the Samsung customer service line for your country and see if they can help you out with the firmware.

[Hauke]

Re: Samsung UE55KS8090 - Mainboard replacement failed

Thank you nomoresonys! I managed to do a factory reset. I pressed INFO -> MENU -> MUTE -> POWER. After the TV booted completely I pressed OK several times to select the factory reset.

Now the TV starts with the initialization sounds, but the screen is dark. The backlight is alright.
At this site I found some pictures of the service menu: https://forum.samygo.tv/viewtopic.php?f=94&t=10732
There are some configurations about LVDS, T-CON and Panel available in the service menu. I think "LVDS format", "Panel EEPROM upgrade" and "Panel flash upgrade" are interesting. But I don´t know what these really mean...

Maybe I will try to call samsung tomorrow. I never had luck with customer support until now, but maybe they can help me.


Edit: I found this menu in an other Samsung UHD TV of mine (Picture attached). Maybe this could be the reason? But how to select the right one if I cant see anything..

[petehall347]

Re: Samsung UE55KS8090 - Mainboard replacement failed

is there a setting for panel id number or size ?

[Diah]

Re: Samsung UE55KS8090 - Mainboard replacement failed

After reflashing all EEPROM and Flash ICs on my original mainboard it starts. Now I can hear the starting sound and the backlight comes up. But the panel stays black.

connect this TV with black screen to other working set via scart cable to take look on the screen what it show you.. even the SM could be displayed.

[Hauke]

Re: Samsung UE55KS8090 - Mainboard replacement failed

is there a setting for panel id number or size ?

I will search for it. The only thing I found until now was the panel selection menü.

connect this TV with black screen to other working set via scart cable to take look on the screen what it show you.. even the SM could be displayed.

I never heard of something like this. This sounds awesome.
I checked the one connect box and the mainboard - I can´t find any scart output. Is there an other way to get the video output?

[Diah]

Re: Samsung UE55KS8090 - Mainboard replacement failed

I never heard of something like this. This sounds awesome.
I checked the one connect box and the mainboard - I can´t find any scart output. Is there an other way to get the video output?

your set as other new set with new version of scart cable ( adapter ) you have this adapter plug on the TV

[nomoresonys]

Re: Samsung UE55KS8090 - Mainboard replacement failed

The SCART connection may be called EXT RGB on some tvs.